Recording medium for storing virtually deleted still picture information, recording and/or reproducing method and apparatus therefor

ABSTRACT

A recording medium for storing virtual deletion information, and recording and/or reproducing method and apparatus therefor are provided. The recording medium includes a first region having a plurality of still pictures, and a second region having first virtual deletion information for the still pictures, and still picture group information for separating the still pictures in the first region into a predetermined maximum number of groups in order to manage the still pictures at a group level, wherein the first virtual deletion information is within the still picture group information, and if the first virtual deletion information is set to a virtual delete state, the corresponding still picture is not to be reproduced. Accordingly, file extent information can be prevented from excessively increasing by maximally preventing a recording area from being scattered, when some of a data file are deleted by a user&#39;s request.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of application Ser. No. 09/339,190,filed Jun. 24, 1999, now U.S. Pat. No. 6,757,476, and claims the benefitof Korean Application No. 98-23991, filed Jun. 24, 1998 and KoreanApplication No. 98-44804, filed Oct. 26, 1998, in the Korean PatentOffice, the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to recording and/or reproducinginformation, for effectively processing a still picture, and moreparticularly, to a recording medium for storing virtual deletioninformation for preventing file extent information from excessivelyincreasing when some of a data file is deleted by a user's request, andrecording and/or reproducing method and apparatus therefor.

2. Description of the Related Art

FIG. 1 shows a connection structure for various kinds of information ina moving picture and moving picture data, in recording/reproducing audioand/or video data on a recordable and/or rewriteable recording medium,specifically, a digital versatile disk (DVD), and more precisely, itillustrates the relationship between program chain (PGC) information 11for treating data logically, moving picture information 12 includingvideo object (VOB) information, and a moving picture data file 13 inwhich actually compressed audio/video (A/V) data are recorded in VOBunits.

First, terms used throughout the specification will now be described.Supposing a movie was recorded in first and second parts, the overallmovie is a program chain (PGC) and the first and second parts areprograms. Also, each program can be defined by further dividing the sameinto several cells called sub-units. The information in each cell canwholly or partially define a video object (VOB). In such an event, eachcell is used as a basic accessing unit during reproduction, and theprogram and PGC are only the information for connectivity between aplurality of cells.

Also, since data is actually sub-divided into video object units (VOBUs)and recorded in a moving picture data file, the VOB information includesvarious kinds of information relating to the VOBU data, that is, VOBU#1, VOBU #2, . . . and the VOB data in the moving picture data file isaccessed by the VOB information. Here, the VOB data is used as a randomaccess unit of a disk recording/reproducing apparatus. The VOBU is basedon a single GOP (Group of Pictures) in the case of an MPEG (MovingPicture Experts Group) video, and audio data corresponding to video datais collected, that is, A/V data is multiplexed into sectors, toconstitute a VOBU.

The data format shown in FIG. 1 is concerned with the moving picture, inwhich the unit of actual data, the VOB, comprises moving picture datafor a fixed period of time. Synchronization or encoding of A/V signalsis performed in units of VOBs. However, in the case of a still picture,each VOB constitutes a still picture. When a VOB is designated in a cellstructure, a cell is necessary for each still picture. Thus, as morestill pictures are recorded, more information is added.

Generally, data errors may be generated if data is recorded on arecordable disk a predetermined number of times. Thus, there is a limitin the number of times for rewriting data on a disk. All information isstored in the memory of a controller for controlling the system for thepurpose of limiting the number of recording times and rapidly accessingdata. However, as described above, in the case of a still picture, ifthe amount of information is increased, much time is required forreading the information. Also, there is a limit to the amount ofinformation that can be stored in a memory with a limited size.Accordingly, it is not possible to record a large-capacity stillpicture.

In a two-dimensional recording medium such as a disk, a file may bedistributed in physically fragmented spaces to then be recorded, andinformation which connects the scattered areas is recorded in a filesystem as file extent information. File extent information isinformation for logically connecting a file having the scattered areasand generally represents the scattered areas sequentially as startpositions and lengths of data. Referring to FIG. 2, for example, a fileis distributed and recorded in two parts, each represented by a startposition and length of data in the file extent information. If a portionindicated by “A” shown in FIG. 2 is deleted so that the file isdistributed in three parts, the amount of file extent information isincreased, as shown in FIG. 3.

In other words, as shown in FIG. 3, the amount of file extentinformation is determined according to the level of fragmentation of afile, irrespective of the size of the file. Therefore, when a pluralityof still pictures are recorded in a file, if some still pictures aredeleted by a user's request, thus causing fragmentation of the file, theamount of the file extent information is sharply increased.

SUMMARY OF THE INVENTION

To solve the above problems, it is a first object of the presentinvention to provide a recording medium for grouping a plurality oflarge-capacity still pictures for the purpose of managing the same at astill picture group level, and for storing still picture groupinformation containing information for virtually deleting a desiredstill picture.

It is a second object of the present invention to provide a recordingmedium for grouping a plurality of additional audio data other thanoriginal audio data added to still picture data, for the purpose ofmanaging the same at an additional audio group level, and for storingadditional audio group information containing information for virtuallydeleting additional audio data.

It is a third object of the present invention to provide a recordingand/or reproducing method and apparatus for grouping a plurality of alarge-capacity still pictures and incorporating virtual deletioninformation into the information managed at a still picture group levelfor the purpose of virtually deleting a desired still picture andoriginal audio data corresponding thereto.

It is a fourth object of the present invention to provide a recordingand/or reproducing method and apparatus for grouping a plurality ofadditional audio data relating to still pictures and incorporatingvirtual deletion information into the information managed at anadditional audio group level for the purpose of virtually deleting theadditional audio data corresponding to the virtually deleted stillpicture.

Additional objects and advantages of the invention will be set forth inpart in the description which follows and, in part, will be obvious fromthe description, or may be learned by practice of the invention.

To achieve the first object, there is provided a recording mediumincluding a first region having a plurality of still pictures, and asecond region having first virtual deletion information for the stillpictures, and still picture group information for separating the stillpictures in the first region into a predetermined maximum number ofgroups in order to manage the still pictures at a group level, whereinthe first virtual deletion information is within the still picture groupinformation, and if the first virtual deletion information is set to avirtual delete state, the corresponding still picture is not to bereproduced.

To achieve the second object, there is provided a method for recordingand/or reproducing audio and/or video data on a recordable and/orrewriteable recording medium including (a) recording a plurality ofinput still pictures, and (b) separating the plurality of still picturesinto a predetermined maximum number of groups, and recording stillpicture group information having first virtual deletion information forthe respective still pictures set to a virtual delete state by a userand playback information related to reproduction.

Also, the method according to the invention further includes the stepsof reading the still picture group data to be reproduced in accordancewith the playback information, and calculating the position of a desiredstill picture in accordance with the read still picture group data andreproducing still picture data located at the calculated position, whilenot reproducing still picture data having the first virtual deletioninformation contained in the read still picture group data set to avirtual delete state.

The apparatus according to the present invention includes a recordingprocessor for signal-processing a plurality of still pictures to berecorded in a first region of the recording medium, and a controller forcontrolling first virtual deletion information for still pictures set toa virtual delete state by a user, the first virtual deletion informationcontained within still picture group information for separating thestill pictures in the first region into within a predetermined maximumnumber of groups in order to manage the still pictures at a group level,for generating playback information related to a reproduction order, andfor controlling the generated playback information to be recorded in asecond region of the recording medium.

According to another aspect of the invention, the apparatus furtherincludes a playback processor for reproducing still picture data in thefirst region based on the still picture group information in the secondregion, while not reproducing still picture having the first virtualdeletion information set to a virtual delete state.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects and advantages of the present invention will becomemore apparent by describing in detail preferred embodiments thereof withreference to the attached drawings in which:

FIG. 1 illustrates a connection structure for various kinds ofinformation and data in a moving picture;

FIG. 2 shows an example of file recording positions and file extentinformation;

FIG. 3 illustrates the relationship between the distribution of a fileand the file extent information;

FIG. 4 shows an example of an overall information structure of arecording medium according to the present invention;

FIG. 5 shows the relationship between various kinds of information andstill picture data in a still picture according to the presentinvention;

FIG. 6 is a block diagram of a recording/reproducing apparatus accordingto the present invention;

FIG. 7 shows the relationship between still picture data and stillpicture group information according to the present invention;

FIG. 8 shows the relationship between additional audio data added tostill picture data and additional audio group information according tothe present information;

FIG. 9 shows the relationship between cell information and still picturegroup information;

FIG. 10 shows the relationship among cell information, still picturegroup information and additional audio group information;

FIG. 11 illustrates a virtually deleted still picture file and stillpicture group information in accordance with a still picture deletioncommand;

FIG. 12 illustrates a virtually deleted additional audio data file andadditional audio group information in accordance with a still picturedeletion command;

FIG. 13 illustrates actual deletion of a still picture file and stillpicture group information in accordance with a deletion command for allstill pictures in a still picture group;

FIG. 14 illustrates actual deletion of an additional audio data file andadditional audio group information in accordance with a deletion commandfor all still pictures in an additional audio group;

FIG. 15 illustrates the structure of still picture group informationaccording to the present invention;

FIG. 16 is a table showing an example of the detailed contents of thestill picture group general information shown in FIG. 15;

FIG. 17 illustrates the structure of a map table for a still pictureshown in FIG. 15;

FIG. 18 is a table showing an example of the detailed contents of avideo map in the map table shown in FIG. 17;

FIG. 19 is a table showing an example of the detailed contents of anoriginal audio map connected to the video map shown in FIG. 18;

FIG. 20 illustrates the structure of additional audio group informationfor a still picture according to the present invention;

FIG. 21 is a table showing an example of the detailed contents ofadditional audio group general information for the still picture shownin FIG. 20;

FIG. 22 illustrates the structure of an additional audio map table forthe still picture shown in FIG. 20;

FIG. 23 is a table showing an example of the detailed contents of theadditional audio map table for the still picture shown in FIG. 22;

FIG. 24 is a table showing an example of the detailed contents of cellinformation for the still picture shown in FIGS. 9 and 10;

FIGS. 25A and 25B illustrate a flow chart showing a method for recordinga still picture according to a first embodiment of a present invention;

FIG. 26 is a flow chart showing a method for recording additional audiodata after recording a still picture according to the first embodimentof the present invention;

FIG. 27 is a flow chart showing a method for reproducing a still pictureaccording to the first embodiment of the present invention;

FIGS. 28A and 28B are flowcharts showing a method for reproducing astill picture according to a second embodiment of the present invention;

FIG. 29 is a flow chart showing a method for reproducing a still pictureaccording to a third embodiment of the present invention; and

FIGS. 30A and 30B illustrate a flow chart showing a method for deletingdata using virtual deletion information according to the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of recording media for storingvirtual deletion information for a still picture, and a recording and/orreproducing method and apparatus therefor, examples of which areillustrated in the accompanying drawings, wherein like referencenumerals refer to the like elements throughout. The embodiments aredescribed below in order to explain the present invention by referringto the figures.

FIG. 4 shows an example of an overall information structure according tothe present invention, in which information including PGC information,moving picture information and still picture information can be recordedin an information file or an information area.

Here, PGC general information contains information such as the number ofprograms in a PGC. Program general information contains information suchas the number of cells in a program. The cell information designates aVOB in the case of a moving picture, as shown in FIG. 1, and designatesa still picture VOB group (to be abbreviated as “still picture group”for brevity) instead of a VOB, in the case of a still picture, as shownin FIG. 5. Since the moving picture information has already beendescribed with reference to FIG. 1, a description thereof will beomitted herein and still picture information according to the presentinvention will now be described. Still picture general informationcontains information relating to the number of kinds of still picturegroup information, and additional audio general information for thestill picture contains information relating to the number of kinds ofadditional audio group information.

FIG. 5 shows the connection structure of various kinds of informationand still picture data in a still picture. In other words, in a stillpicture recorded in units of VOBs in a data file, a plurality of VOBsfor still pictures are managed by a still picture group, and cellinformation contained in the PGC information 21 designates still picturegroup information (GVOB), rather than a single VOB information. Also,audio data may be recorded in addition to the still picture. The audiodata is recorded consecutively after the still picture is recorded,thereby reducing the search time of a reproducing head duringreproduction. The audio data recorded together with the still picture iscalled original audio data, which is contained in the still picturegroup. In the present invention, unless specifically defined, a stillpicture represents both one having only a video part and one having theoriginal audio part and the video part. By managing the still picture bygrouping the same in such a manner, the amount of cell information andstill picture information can be reduced. For example, video codingattributes or original audio coding attributes in a still picture groupare assimilated thus forming still picture group general information,and stored as common information. For the respective still pictures, thepositions thereof in the still picture data file must be indicated. Inthe case when the still pictures are not separated into a plurality ofgroups, the start positions of the respective still pictures must beindicated. However, in the case when the still pictures are grouped, thestart position at which the pertinent still picture group starts to berecorded in a file is stored in the still picture group generalinformation and then only the sizes of the respective still pictures arerecorded as the information for the respective still pictures. Since theamount of information indicative of the size of still picture data,i.e., the number of bytes, is generally less than that indicative of theposition in a file, the overall amount of information can be reduced.

A user may add separate additional audio data to a desired still pictureafter recording the still picture and original audio data on a stillpicture file 23. At this time, only the additional audio data arecollected and recorded in a separate area in the additional audio datafile 24 or the still picture file 23, with the original audio data beingretained. The additional audio data are also managed by grouping in thesame manner as in the still picture data and the concept thereof is thesame as that of the still picture data. In other words, a plurality ofadditional audio data having the same attributes, e.g., audio codingattributes, are grouped into an additional audio group (to beabbreviated as “GAOB”) and then additional audio group generalinformation is recorded as common information. For the respectiveadditional audio data AOBs, only the size information is recorded. Theadditional audio group general information contains the start positionsof audio data in the respective additional audio groups (GAOBs). Theconnection information for the additional audio data added to thespecific still picture, which is indicated by thick arrows in FIG. 5, ispresent in the still picture group information GVOB #1, GVOB #2, . . .In other words, additional audio group identification information fordesignating additional audio data existing in the still picture groupinformation and additional audio identification information in thepertinent additional audio group are contained in the still picturegroup information.

In order to locate a recording position of a specific still picture inthe still picture group, the start position of the still picture groupdata contained in the still picture group general information is addedto the size of the data preceding the still picture to be located.Likewise, in order to search the recording position of specificadditional audio data, the start position of the additional audio groupdata contained in the additional audio group general information isadded to the size of the data preceding the additional audio data to belocated.

In the case of a still picture group, video parts and audio parts areconsecutively recorded in a file or space. Thus, the video informationand the audio information each containing the size thereof are alsorecorded in the bitstream order in which the video data and the originalaudio data are actually recorded. In the case of an additional audiogroup, there is only the additional audio data. Thus, only theadditional audio information is recorded in the bitstream order in whichthe additional audio data is actually recorded.

Thus, as shown in FIG. 5, there is the still picture file 23 to whichthe original audio data may be added, the additional audio data file 24added to the still picture and the information file containing the PGCinformation 21 and the still picture information 22 having the stillpicture group information (GVOB) and the additional audio groupinformation (GAOB). However, the additional audio data may be recordedin a separate area of the still picture file 23, rather than in theadditional audio data file 24. The still picture file 23 can bedesignated by a first region, the additional audio data file 24 can bedesignated by a second region, and the information file containing thePGC information 21 and the still picture information 22 can bedesignated by a third region which is a logic region.

FIG. 6 is a block diagram of a recording/reproducing apparatus forimplementing the present invention. The function of an apparatus forrecording/reproducing A/V (audio/video) data using a recordable andrewriteable disk is largely divided into recording and reproduction.

During recording, an AV codec 110 compression-codes an externallyapplied A/V signal by a predetermined compression scheme and suppliessize information for compressed data. A digital signal processor (DSP)120 receives A/V data supplied from the AV codec 110, adds additionaldata for ECC (error correction code) processing thereto and performsmodulation using a predetermined modulation scheme. A radio frequencyamplifier (RF AMP) 130 converts electrical data supplied from the DSP120 into an RF signal. A pickup 140 drives a disk and records the RFsignal supplied from the RF AMP 130, incorporating an actuator forfocusing and tracking. A servo 150 receives information necessary forservo control from a system controller 160 and stably performs a servofunction. The system controller 160 controls the overall system throughinterfacing with a user to thus control the still picture to be recordedon the disk and record separate information for the recorded stillpicture. Still picture data are managed at a group level by constructingthe still picture group information of the information for therespective still pictures, including size information of still picturedata, size information of original audio data, playback time informationof original audio data and the like, and the position information of therespective still pictures, in the recording order of recorded stillpictures and audio data. When additional audio data is added to a stillpicture, the added additional audio data is recorded in a different filefrom or in the same file as that for the still picture but in adifferent area from that of the still picture. Additional audio data aremanaged at a group level by constructing additional audio groupinformation of the information for recorded additional audio data,including size information of additional audio data, playback timeinformation of additional audio data and the like, and positioninformation of the respective additional audio groups. The informationfor the respective still pictures includes information indicative of theadded additional audio data.

In the case when a user intends to delete an arbitrary still picture viaa user interface, the system controller 160 does not to actually deletethe still picture but sets deletion information in the still picturegroup information to a virtual delete state so that it is virtuallydeleted. In other words, since data is not reproduced during playbackalthough it actually exists, it appears to the user that the data isdeleted. In such a manner, if a specific still picture is virtuallydeleted and original audio data is recorded in sequence with the stillpicture, the original audio data is not reproduced either. Also, ifadditional audio data is added to the still picture, virtually deletedadditional audio information in the additional audio group informationis set to a virtual delete state so that although the additional audiodata exists actually, it appears to the user that the additional audiodata is deleted.

Cell information concerning the reproduction order is recorded as wellas the above-described information. The cell information containsinformation indicative of the recorded still picture group so that therecorded still picture and audio data can be reproduced.

During playback, the pickup 140 picks up the optical signal from thedisk having data stored therein and the data is extracted from theoptical signal. The RF AMP 130 converts the optical signal (that is, RFsignal) into electrical data, and extracts a servo signal for performinga servo function, and modulated data. The DSP 120 demodulates modulateddata supplied from the RF AMP 130 corresponding to the modulation schemeused during modulation, performs an ECC process to correct errors andeliminates added data. The servo unit 150 receives information necessaryfor servo control from the RF AMP 130 and the system controller 160 andstably performs a servo function. The AV codec 110 decodes thecompressed A/V data supplied from the DSP 120 to output an A/V signal.The system controller 160 controls the overall system for reproducingthe user's desired data (still picture only, still picture+originalaudio data or still picture+additional audio data) using the cellinformation and still picture group information stored on the disk whileperforming user interfacing such as processing of the user's key inputs.

In other words, in order to reproduce a specific still picture and audiodata, the still picture group information having the still picture to bereproduced is obtained from the cell information, information such asthe size of the still picture data and the information for the data sizeand playback time of original audio data, if any, is obtained from thestill picture group information, thereby reproducing only desired data.Also, if additional audio data is added to the still picture, desiredadditional audio data is reproduced using information for the data sizeor playback time of the additional audio data from the additional audiogroup information pointed to by the still picture group information.

Also, if virtually deleted still picture information is read from thestill picture group information, the corresponding still picture andoriginal audio data are not reproduced so that although the dataactually exists, it seems to the user that it does not exist. Likewise,if the added additional audio data is virtually deleted, it is notreproduced.

Here, the A/V codec 110, the DSP 120, the RF AMP 130 and the pickup 140operating during recording can be referred to as a recording processor.Also, the pickup 140, the RF AMP 130, the DSP 120 and the AN codec 110operating during playback can be referred to a reproduction processor.

FIG. 7 shows the relationship between still picture data and stillpicture group information, in which the information for a plurality ofstill pictures (e.g., 64 maximally) having the same attributes isrecorded in the respective still picture group (GVOB) information 201.The number of the still pictures forming each still picture group isdetermined such that it is within the limit of the maximum number ofstill pictures. Each still picture group information 202 includes stillpicture group general information and information for the respectivestill pictures and is information for still picture data 203 composed ofvideo parts and video or audio parts in a sequence of bitstreamsrecorded. The still picture group general information has the startaddress of the corresponding still picture group.

Also, as information for the respective still pictures, still pictureinformation having original audio data exists in the form of mapinformation including video part information for video parts and audiopart information for audio parts. Here, a video map and an audio map fora still picture have the same identification information. If the stillpicture information is includes only a video part, it exists in the formof a map having only the video part information. In the still picturegroup information 202, virtual deletion information for virtuallydeleting both a still picture and original audio data added thereto ispresent. Here, still picture data is recorded in a VOB.

FIG. 8 shows the relationship between additional audio data added to astill picture and additional audio group information according to thepresent information, in which additional audio group (GAOB) information211 includes information for additional audio data recorded in units ofa plurality of additional audio groups. Additional audio groupinformation 212 has additional audio group general informationcontaining the start address of the corresponding additional audio groupand audio maps (AMAPs) following the sequence of additional audio data.The information for additional audio data 213 including an additionalaudio part of a still picture is recorded in each additional audio map,inclusive of size information of the additional audio data thereof.Also, the additional audio group information 212 includes virtualdeletion information for virtually deleting the respective audio parts.

FIG. 9 shows the relationship between cell information (which can alsobe referred to as playback information ) and still picture groupinformation, in which a cell is a logical unit in relation to indicationof a reproduction order. The cell information includes still picturegroup identification information (GVOB_ID), still picture reproductionstart identification information (START VOB_ID) of the correspondingstill picture group and still picture reproduction ending identificationinformation (END VOB_ID). The cell information may correspond to all thestill picture groups or may correspond to some of the still picturegroups which are intended to be reproduced.

The additional audio data are stored in a separate area from the stillpicture data, that is, in a different file or in a different area of thesame file from or as that of the still picture data.

For example, in the case when the additional audio data is stored in aseparate file from the still picture data, as shown in FIG. 7, GVOB #1,#2 and #3 having still picture data constitute a file. Also, as shown inFIG. 8, GAOB #1, #2 and #3 having additional audio data constitute afile. Thus, in the case of recording/reproducing actual still picture oradditional audio data, the still picture or additional audio data isaccessed using the information of each file.

Alternatively, in the case when the additional audio data and the stillpicture data are stored in one and the same file, GVOB #1, #2 and #3 andGAOB #1, #2 and #3 shown in FIGS. 7 and 8 constitute a file. Inconstituting the file in such a manner, the respective GVOBs and GAOBsmay be mixed in the recording order, for example, in the order of GVOB#1, GVOB #2, GAOB #1, GVOB #3, GAOB #2 and GAOB #3. Otherwise, the GVOBsand GAOBs are coupled and arranged in each batch to constitute a file.

FIG. 10 shows the relationship among cell information, still picturegroup information and additional audio group information, fordesignating desired additional audio data in the additional audio grouprecorded in a separate area as well as original audio data as the audiodata added to a still picture. The cell information includes stillpicture group identification information (GVOB_ID), still picturereproduction start identification information (START VOB_ID) in thecorresponding still picture group and still picture reproduction endingidentification information (END VOB_ID). Video part information in theinformation for still picture group GVOB #1 may have information fordesignating additional audio data added to a still picture, that is,additional audio group identification information and additional audioidentification information in the corresponding additional audio group.For example, additional audio group identification information GAOB #jand identification information #2 indicating that the additional audiodata is the second audio map in the GAOB #j exist in the video partinformation for a still picture #2 of the still picture group GVOB #i.

In the present invention, when a plurality of still pictures arerecorded in a file and still pictures are deleted and fragmented inseveral parts by a user's request, to avoid an abrupt increase in fileextent information, a plurality of still pictures are grouped andmanaged at a still picture group level, and each still picture hasvirtual deletion information. Thus, even if a user deletes a stillpicture, the still picture is not actually deleted from the file butappears to be deleted since they are not reproduced according to thevirtual deletion information. In some cases, the user deletes stillpictures for the purpose of securing empty space (free area) forrecording new data thereon in addition to avoidance of reproduction ofdata. In this case, since the data is not actually deleted, the emptyspace cannot be secured just by using the virtual deletion information.If all of the still pictures in the still picture group information arevirtually deleted, they are actually deleted from the file in units ofstill picture groups, thereby securing a free area. In other words,since a still picture group is formed by a plurality of still pictures,a considerable amount of free space is produced by deleting the same.

As shown in FIG. 11, if a still picture deletion command is input by auser through an input device 301 such as a key pad mounted on a stillpicture output device 302 or a remote controller, virtual deletioninformation out of the information for the corresponding still picturein the still picture group information is set to “1” indicative of avirtual delete state, without change in an actual still picture file304. Since there is no change in the actual still picture file 304, thefile area information for the still picture file is not increased. Thevirtual deletion information is commonly applied to the original audiodata added to the still picture. In other words, if a still picture isvirtually deleted, the original audio data is also considered to havebeen deleted. Here, if the virtual deletion information set to “1” iscleared to “0”, the still picture can be restored.

However, if additional audio data is added to a still picture, insteadof the virtual deletion information (which can be referred to as firstvirtual deletion information) for a still picture, as shown in FIG. 12,the virtual deletion information in additional audio group information(which can be referred to as second virtual deletion information) can beused. If a still picture deletion command is input by a user through aninput device 311, virtual deletion information for the correspondingstill picture in the still picture group information is set to “1”indicative of a virtual delete state and virtual deletion informationfor additional audio data in the additional audio group information 314for the still picture is also set to “1”. Thus, the correspondingadditional audio data in an additional audio file 315, is not actuallydeleted either. Here, if the virtual deletion information set to “1” iscleared to “0”, the additional audio data can be restored.

Actual deletion of a file occurring in a still picture group oradditional audio group will be described with reference to FIGS. 13 and14. In other words, when all the information in a group is virtuallydeleted, the group can be actually deleted from a file.

As shown in FIG. 13, if a still picture deletion command, for virtuallydeleting all still pictures in the information for a still picture group#2, is input by a user through an input device 321 and virtual deletioninformation in the information for a still picture group #2 in the stillpicture group information 323 is set to “1” indicative of a virtualdelete state, the information for a still picture group #2 in the stillpicture group information 323 is deleted so that updated still picturegroup information 324 is created and data for GVOB #2 in a still picturefile 325 is actually deleted to be allocated as a free area. Therefore,even if a plurality of still pictures are deleted, a discontinuoussection in a still picture file is determined by deletion of the entiregroup, so that the file area information is increased by a small amount.In FIG. 13, identification numbers for still picture groups aresequentially given again. However, if the identification numbers areexpressly stored in the still picture group information, they can beretained as they are.

Similarly, data of an additional audio group file can be actuallydeleted. As shown in FIG. 14, virtual deletion information for thecorresponding still pictures in still picture group information 331 isset to “1” indicative of a virtual delete state by a still picturedeletion command, and the virtual deletion information of the entireadditional audio information of the information for a still picturegroup #3 in additional audio group information 332 corresponding to thestill pictures set to a virtual delete state, is set to a virtual deletestate “1”.

The information for the additional audio group #3 in the additionalaudio group information 332 is deleted and updated additional audiogroup information 333 is created. Data for GAOB #3 in an actual audiofile 334 is deleted to be allocated as a free area. In this case, thefile extent information is increased by a very small amount. In FIG. 14,identification numbers for additional audio groups are sequentiallygiven again. However, if the identification numbers are expressly storedin the additional audio group information, they can be retained as theyare.

FIG. 15 illustrates the structure of still picture group informationaccording to the present invention, which includes still picture groupgeneral information and a still picture map table, and may furtherinclude attribute information for a still picture such as picture sizesor video encoding modes.

FIG. 16 is a table showing an example of the detailed contents of stillpicture group general information shown in FIG. 15, which includesGVOB_ID representing information for identifying a still picture groupin a still picture file, GVOB_S_ADR representing the start address offirst still picture data in the corresponding still picture group in thestill picture file, GVOB_Ns representing the number of still pictures inthe still picture group, GVOB_Ds representing the number of virtuallydeleted still pictures in the corresponding VOB group, and so on. IfGVOB_Ds and GVOB_Ns are equal to each other, the VOB group can bedeleted from a file. If GVOB_Ds is not stored expressly, it is checkedwhether all still pictures in the corresponding still picture group arein a virtually deleted state to then be actually deletable. Also, theidentification information GVOB_ID can be expressly recorded as a uniqueone for each still picture group in a still picture file or can besuggestively indicated in the order of still picture groups, that is,#1, #2, . . .

FIG. 17 illustrates the structure of the still picture map table shownin FIG. 15. There are two types of maps; one is video maps VMAPs forvideo parts and the other is audio maps AMAPs for original audio partsadded to the still pictures. The order of maps is the same as that ofdata of recorded bitstreams in a still picture file as shown in FIG. 7.Thus, in the case when a still picture has only a video part, there isonly a video map. In the case when a still picture has original audiodata in addition to the video part, both a video map and an audio mapare recorded and are practically considered as one map using the sameidentification information.

FIG. 18 is a table showing an example of the detailed contents of avideo map in the map table shown in FIG. 17, containing MAP_TYindicating the type of a corresponding map and represented by a binary“0” in the case of a video map for a video part, VOB_ID indicatingidentification information for the video part and ranging from 1 to 64in this embodiment. Also, VOB_ID can be expressly indicated orsuggestively indicated in the recording order, that is, #1, #2, #3, . ..

Also, the video map contains V_DELETE which is a binary value indicatingdeletion or non-deletion of a VOB, that is, indicating that a VOB is notdeleted if the value thereof is “0” and that the VOB is virtuallydeleted if the value thereof is “1” V_PART_SZ indicating the size of avideo part, GAOB_ID which is identification information of an additionalaudio group, the value of which exists if a still picture has additionalaudio data, and the value of which is “0” if a still picture does nothave additional audio data, and AOB_ID which is identificationinformation of additional audio data in an additional audio group if astill picture has additional audio data, and the value of which is “0”if the still picture does not have the additional audio data.

Here, V_DELETE represented by a binary value “1” indicates that a stillpicture is virtually deleted. Thus, if the still picture has originalaudio data, the original audio data is also considered to have beenvirtually deleted. This is because original audio data solely existingafter the still picture is deleted as being meaningless. Also, VOB_IDand V_PART_SZ can be referred to as still picture position information,and GAOB_ID and AOB_ID can be referred to as additional audioconnectivity information.

FIG. 19 is a table showing an example of the detailed contents of anoriginal audio map, containing MAP_TY indicating the type of acorresponding map and represented by a binary value “1” in the case ofan audio map for an audio part, A_PBTM indicating the playback time ofan audio part and A_PART_SZ indicating the size of the audio part.

FIG. 20 illustrates the structure of additional audio group informationfor a still picture according to the present invention, containingadditional audio general information and an additional audio map tablefor the still picture. Also, additional audio attribute information forthe still picture may be further included.

FIG. 21 is a table showing an example of the detailed contents ofadditional audio general information for a still picture, shown in FIG.20, containing GAOB_ID indicating identification information for anadditional audio group in an additional audio file, GAOB_S_ADRindicating the start address of the first additional audio data in thecorresponding additional audio group in the additional audio file, andGAOB_Ns indicating the number of additional audio parts contained in theadditional audio groups. GAOB_ID can be expressly indicated orsuggestively indicated in the recording order.

FIG. 22 illustrates the structure of an additional audio map tableconsisting of n additional audio maps for additional audio parts shownin FIG. 20.

FIG. 23 is a table showing an example of the detailed contents of theadditional audio map table for the still picture shown in FIG. 22,containing AOB_ID indicating identification information for a specificaudio part in an additional audio group and ranging from 1 to 64 in thisembodiment, A_DELETE indicating whether an additional audio part isvirtually deleted or not, A_PBTM indicating the playback time ofadditional audio data and A_PART_SZ indicating the size of additionalaudio data such as the number of sectors. Here, AOB_ID can be expresslyindicated or suggestively indicated in the recording order, that is, #1,#2, #3, . . .

FIG. 24 is a table showing an example of the detailed contents of cellinformation for a still picture, shown in FIGS. 9 and 10, containingS_GVOB_ID indicating identification information for a still picturegroup, S_VOB_ID indicating identification information for a stillpicture in which reproduction starts, and E_VOB_ID indicatingidentification information for a still picture in which reproductionends.

FIGS. 25A and 25B illustrate a flow chart showing a method for recordinga still picture according to a first embodiment of the presentinvention, that is, a method for recording a still picture and originalaudio data. First, it is determined whether a still picture or both astill picture and original audio data are recorded (step S101). Stillpicture group information is generated, identification for a stillpicture group is allocated, the number of still pictures in the stillpicture group is set to “0” and the start address of the still picturegroup in a still picture file is recorded (step S102). It is thendetermined whether a recording start signal of a still picture is inputby a user or not (step S103). If the recording start signal is input,the still picture is recorded in the still picture file, identificationinformation for the still picture is allocated to the still picturegroup information, the number of still pictures in the still picturegroup is increased by one and the size information of the still picturesis recorded in the video map (step S104).

It is determined whether or not a mode set by a user is for recordingboth a still picture and original audio data (step S105). If yes, theaudio data for the still picture is recorded following the correspondingstill picture on the still picture file and the audio size informationis recorded in an audio map in the still picture group information (stepS106).

It is determined whether the number of still pictures recorded is themaximum number possible to constitute the information for a stillpicture group (e.g., 64 maximally) (step S107). If the still picturegroup information is completed, the procedure returns to step S102 togenerate another still picture group information. Otherwise, theprocedure proceeds to step S103 to determine whether a recording startsignal of a still picture is input by a user or not.

If the mode set by a user is for recording only a still picture in stepS105, step S106 is skipped and the procedure proceeds to step 107 torecord the next still picture. If the recording start signal of a stillpicture is not input by a user in step S103, it is determined whether ornot to terminate recording (step S108). If it is determined to terminaterecording, cell information is recorded and the procedure ends (stepS109). Here, the cell information is created for every still picturegroup so as for all still pictures to be reproduced.

FIG. 26 is a flow chart showing a method for recording additional audiodata after recording a still picture according to the first embodimentof the present invention. First, additional audio group information isgenerated, identification information for an additional audio group isallocated, the number of additional audio parts in the additional audiogroup is set to “0” and the start address of the audio group is recordedin an additional audio file (step S201).

It is then determined whether the recording start signal of additionalaudio data is input by a user or not (step S202). If the recording startsignal is input, a specific still picture to which the user desires toadd additional audio data is designated (step S203). The additionalaudio data is recorded in an additional audio file, identificationinformation for additional audio data in the audio map of the additionalaudio group information is allocated, the number of additional audioparts in the additional audio group is increased by one, and the sizeinformation of the additional audio data in the audio map is recorded(step S204). Although it has been described herein that the additionalaudio data is recorded in a different file from that of the stillpicture, the additional audio data can be recorded in a separate area ofthe same file as that of the still picture.

Identification information for the still picture group of apredetermined still picture and identification information for the stillpicture are read and the information for the still picture, that is,identification information for an additional audio group for additionalaudio parts and identification information for additional audio data,are recorded in the video map for the predetermined still picture (stepS205).

It is then determined whether the number of additional audio parts in anadditional audio group reaches N, that is, a maximum number toconstitute a group (step S206). If yes, the procedure goes to step S201to generate another additional audio group information. Otherwise, it isdetermined whether the recording start signal of additional audio datais input by a user (step S202). If a recording start signal ofadditional audio data is not input by a user in step 202, the procedureis terminated.

Here, the step of designating a specific still picture (step S203) mayprecede the step of determining whether or not a recording start signalof additional audio data is input by a user (step S202).

FIG. 27 is a flow chart showing a method for reproducing a still pictureaccording to the first embodiment of the present invention, that is, amethod for reproducing a still picture and original audio data addedthereto. Referring to FIG. 27, PGC information and cell information areread (step S301). Identification information for a still picture groupto be reproduced, playback start identification information and playbackending identification information are read from the cell information toread the still picture group information pointed to by the cell (stepS302). Video map information for the video part corresponding to theplayback start identification information in the read still picturegroup information is obtained to read the size of a video part, or bothvideo map information and audio map information are obtained in the caseof a still picture having original audio data to read the size of avideo part and the size of an audio part (step S303).

The position of a desired still picture is calculated by the read videopart information and video data located at the calculated position isread and decoded to reproduce the still picture (step S304). Here, theposition of a desired still picture is obtained by summing the startposition of a still picture group and the size of data preceding thedesired still picture. While the still picture is reproduced, it isdetermined whether original audio data is added to the still picture(step S305). If yes, the original audio data is read and decoded toreproduce the original audio data (step S306). Here, the readingposition of the original audio data is obtained by summing thecalculated position of the still picture and the size of a video part ofthe desired still picture. It is checked whether all still picturesbelonging to a cell are reproduced or not using the cell information andthen it is determined whether or not there is a still picture to bereproduced next (step S307). If yes, the information for the video partof the still picture to be reproduced next is read (step S303).Otherwise, the procedure is terminated. In the case when there are aplurality of series of cell information, this routine is repeated.

Here, the step of determining whether original audio data is added to astill picture (step S305) may be performed directly after the step ofreading the still picture group information (step S302). This is becauseit is possible to determine that original audio data is added to a stillpicture in the case when an audio map for an audio part is addedsubsequently to a video map for a video part, in accordance with thestill picture group information.

FIGS. 28A and 28B illustrate a flowchart showing a method forreproducing a still picture according to a second embodiment of thepresent invention, that is, a method for reproducing a still picture, astill picture having original audio data, or a still picture havingadditional audio data. Referring to FIG. 28A, cell information is readfrom PGC information (step S401) and then still picture groupinformation pointed to by a cell to be reproduced is read (step 402).Information for the start position of a still picture group is read fromthe read still picture group information and the position of a desiredstill picture is calculated (step S403). Here, the position of a desiredstill picture is obtained by summing the start position of a stillpicture group and the size of data preceding the desired still picture.The video data is read and decoded in accordance with the positioninformation of the desired still picture to reproduce the still picture(step S404).

It is then checked whether additional audio data is present in the stillpicture group information or not (step S405). If not, it is checkedwhether there is original audio data (step S406). Here, the presence ofadditional audio data in the map information for the video part of thedesired still picture to be reproduced can be determined using theidentification information for an additional audio group and theidentification information for additional audio data. The presence oforiginal audio data can be known by determining whether there is audioinformation (an audio map) in the map table of the desired still pictureto be reproduced.

If there is original audio data in step S406, the read position of theoriginal audio data is calculated (step S407). Here, the read positionof the original audio data is obtained by summing the calculatedposition of the desired still picture and the size of the video part ofthe desired still picture. Original audio data is read from thecalculated position information of the desired still picture and decodedto reproduce the original audio data (step S408) and the procedureproceeds to step S411 as shown in FIG. 28B.

If additional audio data is present in step S405, that is, if the readidentification information for the additional audio group designated tothe still picture and identification information for the additionalaudio data are not “0”, the start position of the additional audio groupis read from the additional audio group information to calculate theposition of desired additional audio data (step S409 in FIG. 28B). Theposition of desired additional audio data is obtained by summing thestart position of an additional audio group and the size of theadditional audio data preceding the additional audio data having theidentification information for the desired additional audio data in theadditional audio group.

Additional audio data is read from the calculated position informationfor the desired additional audio data and is decoded to reproduce theadditional audio data (step S410). Then, it is determined whether thereis a still picture to be reproduced next (step S411). If yes, theprocedure returns to step S403. Otherwise, the procedure is terminated(step S411). In the case of reproducing a plurality of cells, theoverall procedure is repeated.

Alternatively, instead of step 405 of determining whether additionalaudio data is present or not and step 406 of determining whetheroriginal audio data is present or not, it is first determined using thestill picture group information read in step S402 whether the stillpicture to be reproduced is a still picture having only a video part,one having original audio data added thereto, or one having additionalaudio data added thereto. If the still picture has only a video part,steps S403 and S404 are performed. If the still picture has originalaudio data, steps S403, S404, S407 and S408 are performed. If the stillpicture has additional audio data, steps S403, S404, S409, S410 and S411are performed.

Further, according to another aspect of the present invention, beforereproduction, a reproduction mode is set by interfacing with a user todetermine whether only a still picture is to be reproduced, both a stillpicture and original audio data are to be reproduced, or both a stillpicture and additional audio data are to be reproduced.

FIG. 29 is a flow chart showing a method for reproducing a still pictureaccording to a third embodiment of the present invention, that is, amethod for reproducing data in the case when virtual deletioninformation in a still picture is set to a virtual delete state.Referring to FIG. 29, PGC information and cell information are read(step S501). Identification information for a still picture group to bereproduced, playback start identification information and playbackending identification information are read from the cell information toread the still picture group information pointed to by the cell (stepS502). Video map information for the video part corresponding to theplayback start identification information in the read still picturegroup information is obtained to read the size of the correspondingvideo part and the virtual deletion information (step S503).

When it is determined that the virtual deletion information is set to avirtual delete state, the still picture set to the virtual delete stateshould not be reproduced. Thus, reproduction is skipped and theprocedure proceeds to step S508.

If the virtual deletion information is not set to a virtual delete statein step S504, the position of a desired still picture is calculated bythe read video part information and video data located at the calculatedposition is read and decoded to reproduce the still picture (step S505).Here, the position of the desired still picture is obtained by summingthe start position of the still picture group which includes the desiredstill picture and the size of data preceding the desired still picture.While the still picture is reproduced, it is determined whether audiodata is added to the still picture (step S506). If yes, the audio datais read and decoded to reproduce the audio data (step S507). Here, twotypes of audio data are added to a still picture, that is, originalaudio data recorded with video data of the still picture and additionalaudio data added after recording. Either type or both types of audiodata may exist. If both types of audio data exist, the additional audiodata is automatically reproduced or one type of audio data is selectedby a user to then be reproduced.

Here, the read position of the original audio data is obtained bysumming the calculated position of the still picture and the size of avideo part of the desired still picture. The position of the additionalaudio data is obtained by summing the start position of the additionalaudio group indicated by the still picture group information and thesize of additional audio data preceding additional audio data havingidentification information for the additional audio data in theadditional audio group information.

It is checked whether all still pictures belonging to a cell have beenreproduced or not using the cell information and then it is determinedwhether or not there is a still picture to be reproduced next (stepS508). If yes, the information for the video part of a still picture tobe reproduced next is read (step S503). Otherwise, the procedure isterminated. In the case of reproducing a plurality of cells, the overallprocedure is repeated.

FIGS. 30A and 30B illustrate a flow chart showing a method for deletingdata using virtual deletion information according to the presentinvention, in the case when a user intends to actually delete a specificstill picture and/or additional audio data. Referring to FIG. 30, adeletion command for deleting a specific still picture is input by auser (step S601). In accordance with the deletion command, virtualdeletion information for a still picture in the corresponding stillpicture group information is set to a virtual delete state “1” (stepS602). It is determined whether virtual deletion information for allstill pictures in the corresponding still picture group information isset to a virtual delete state “1” (step S603). If virtual deletioninformation for all still pictures in the corresponding still picturegroup information is set to a virtual delete state “1”, thecorresponding still picture group is actually deleted from the stillpicture information and the still picture group information is updated(step S604). All of the data in the corresponding still picture group isactually deleted from a still picture data file and the area of thecorresponding still picture group is set to a free area (step S605).Other still pictures or moving pictures can be recorded in the free areaand this file area is updated in a file system.

It is determined whether the virtually deleted still picture hasadditional audio data (step S606). If yes, virtual deletion informationfor additional audio data in the corresponding additional audio groupinformation is set to a virtual delete state “1” (step S607). It isdetermined whether virtual deletion information for all additional audioparts in the corresponding additional audio group information is set toa virtual delete state “1” (step S608). If virtual deletion informationfor all additional audio parts in the corresponding additional audiogroup information is set to a virtual delete state “1”, thecorresponding additional audio group is actually deleted from theadditional audio information and the additional audio group informationis updated (step S609). All of the data in the corresponding additionalaudio group is actually deleted from an additional audio data file (stepS610).

As described above, according to the present invention, duringreproduction, a virtually deleted still picture is not reproduced, usingvirtual deletion information. Thus, recording areas can be preventedfrom being scattered when some data files are deleted at a user'srequest, thereby avoiding an abrupt increase in file extent information.

Also, original audio data added to a virtually deleted still picture canbe virtually deleted using virtual deletion information, and additionalaudio data corresponding to the still picture can also be virtuallydeleted. A still picture or additional audio data virtually deleted inunits of groups is actually deleted from a file so that a free area forrecording new data can be secured.

Further, a large number of still pictures, original audio parts addedthereto and additional audio data can be recorded using a minimum amountof information. During reproduction, data can be displayed and edited inunits of still pictures. Also, it is possible to confrontafter-recording of audio data using the additional audio data. Videomaps and/or audio maps for still pictures can be formed in a recordingorder of bitstreams, thereby allowing effective management ofinformation.

1. A recording medium for use with a recording and/or reproducingapparatus, the medium comprising: a plurality of still pictures; virtualdeletion information for the still pictures, the apparatus using thevirtual deletion to determine whether a corresponding one of the stillpictures is currently reproducible upon playback of the recording mediumby the apparatus, the virtual deletion information being at least oneflag detected by the apparatus; and still picture group information usedby the apparatus for separating the still pictures into groups, thestill picture group information including a start position of each stillpicture group and sizes of the respective still pictures within thestill picture group, a number of still pictures within the correspondingstill picture group, and a number of virtually deleted still pictures inthe corresponding still picture group.
 2. The recording medium accordingto claim 1, wherein: the still picture group information includes videomap tables for each of the still pictures, and each video map tablecomprises: a type of a video map for a video part, a video partidentifier, the virtual deletion information for the corresponding stillpicture, a size of the video part, an information identifier of anadditional audio group when the additional audio group exists, and anidentifier of additional audio data in the additional audio group whenthe corresponding still picture has additional audio data associatedtherewith.
 3. The recording medium according to claim 1, wherein: eachstill picture comprises a video part, at least some of the stillpictures comprise an original audio part, the original audio parts arerecorded consecutively after the corresponding video parts, neither thevideo part nor the original audio part of the corresponding stillpicture are reproduced by the apparatus when the virtual deletioninformation thereof is set to the virtual delete state, and the stillpicture group information comprises for each original audio part, a typeof an audio map for an audio part, a playback time of the audio part,and a size of the audio part.
 4. A recording medium for use with arecording and/or reproducing apparatus, the medium comprising: at leastone still picture; first virtual deletion information for the one stillpicture, the apparatus using the first virtual deletion information todetermine whether the one still picture is currently reproducible uponplayback of the recording medium by the apparatus, the first virtualdeletion information being at least one flag detected by the apparatus;one or more additional audio parts added by the apparatus to the onestill picture during playback by the apparatus; second virtual deletioninformation for the additional audio parts, the apparatus using thesecond virtual deletion information to determine whether a correspondingone of the additional audio parts is currently reproducible by theapparatus, and connective information which the apparatus uses todetermine connectivity between still pictures and correspondingadditional audio parts during the playback by the apparatus, wherein:the connectivity information further includes identification informationfor additional audio groups into which the additional audio parts aregrouped and identification information for the additional audio parts inthe corresponding additional audio groups, and additional audio groupinformation including additional audio group general informationcontaining the start position of additional audio groups into which theadditional audio parts are grouped and information relating to a numberof the additional audio parts in each additional audio group, andinformation for the additional audio parts, the information for theadditional audio parts contains position information for the additionalaudio parts in each additional audio group and the second virtualdeletion information for the additional audio parts, and the additionalaudio group information for each additional audio group includes a typeof an audio map for a corresponding one of the additional audio parts,the second virtual deletion information for the additional audio part, aplayback time of the additional audio part, and a size of the additionalaudio part.